Gas hot water heater and copper pipes.

Two days ago, suddenly, we have no water at all when we turn on any hot water faucet but cold works fine throughout the house. I checked pipes and none are broken or cracked. I tried to drain or flush the hot water heater (connected hose to drain spigot on WH, other end in tub) and no water came out when I opened it. I turned on the hot water in bathroom (closest to WH) to releave pressure and nothing. Turned on cold in bathroom and hot water trickled out of the hose. I ran it like this for 30 minutes to try to flush the WH. Only the first few seconds was there any black particles, the rest was clear. The hot pipe leaving the WH was cold to the touch.

Today I tried to open the pressure releif valve (had to find something to fit in space to catch water) and air is released, valve gets hot, but no water comes out. If I open the drain valve (with hose same as above) and then open the pressure releif valve, water flows hot from the hose, still nothing from the pressure releif valve. The hot water pipe leaving the WH now gets hot but still no water from the faucets. Nothing at all.

Turned off cold water supply, opened releif valve and drained WH. Then turned on cold water supply to refill, hot water pipe going out gets hot, still no water at all from hot water faucets.

I am at the point that I think I need a new water heater (several years old and have not maintained it as recommended, oops) but I wanted to get some opinions first since it is still heating water fine, just not getting to the faucets.

Thank you and happy holidays!

I don't know what Geo you are but I keep thinking frozen pipe. When hooking a hose up to the tank lower drain and opening the pressure relief valve its very possible not to get any water out of the pressure relief valve because the HW needs air into it for lower hose to drain and break vacuum. The copper lines coming out of th HW is there 2 shut off valves and if there is one on the hot side( most plumbers don't put on ) does it have a little cap on the side of the valve that's a bleeder and open and to check for hot water? Is the HW in a basement? You said hard to get to the hot water heater, Follow the hot pipe line and does it seem to plumb up an outside wall or under a floor or crawl space? The water supply coming to the heater come up through a floor, or a crawl space? Please describe copper pipe Traver both ways. Need some more details.

I agree with 21boat, That frozen pipes can be the problem, but Let me ask you a few questions,
1. How old is you water Heater?
2. What type of Nipples are installed on the cold and hot side?
3. How is the weather is it at freezing point?
It is normal if you open the heater drain valve and open the T&P valve nothing should come out of the T&P drain line.
Most common problem at this point.
1. Freezing water line to the Heater.
2. Clogged nipples the cold and Hot.
If the weather is at freezing point and you think the pipes are frozen try to put heat on the pipes.
Close the cold shut off valve, open the closet hot faucet, open the water heater drain and open the T&P valve, disconnect both the inlet and out let lines.
Remove both nipples and check for any clog, if they are clogged replace them, and check if your hot water is working now, Good Luck.

John

Thank you both for quick reply. It is very cold here, currently 5 degrees. The WH is in a closet in the center of my ranch style house so not near an exterior wall. I went in to the crawl space below the house and it is fairly warm down there, much warmer than outside. The furnace is also in the crawlspace. I went directly under the WH and couldn't find any broken pipes but can't tell if it could be frozen. The water in and out would travel through the crawlspace, but it seems fairly warm down there.
There is not a valve on the hot side.
After further inspection I found a label with "1991" on it so it's apparently really old. I'm sure it's probably due to be replaced but if it can hold out a few more months (tax season better than holiday season) it would definitely help.
I don't know anything about the nipples but they look like heat trap nipples (found at Amazon.com: Water Heater Heat Trap Nipples: Home Improvement).
If it may be due to frozen pipes, should I wait for warm weather before replacing the water heater? Or try to heat the pipes? I know some water is flowing in because I can get it to come out the hose from the drainage valve. Not much pressure, but some.
What would be the best way to heat the pipes?
Thanks again!

For now try to heat those pipes that travel under the heater and where you think it might be the coldest. Remember it only takes a 1/2 inch frozen spot to stop the water. Look to see if there is any of the copper pipe that is a little bigger. Frozen water will split copper pipe. Use a good heater or a (blow torch) and be careful with this hair dryer takes a little longer but its safe. I still think it's a frozen pipe because it shut down to quick "afaroo" has a good list to check. If the nipples were getting slowly cloged you would have seen a slower progression on hot water getting less over time but it was real quick no hot water Is 5 degrees not good. If it is frozen and you get it to work. Let your faucets slightly run Not just a drip drip. And to get through the season and to keep the line from freezing get some heat tape and wrap the pipe in the problem Area. Try Heat and I am curious to see and help solve your problem
Thanks and good luck!

I went in the crawlspace and used a hair dryer on the cold pipe going in to the WH for a long time. No pipes are swollen but that is the only place I don't feel water moving through. I felt all of the pipes with water being turned on, hot, then cold to hot, throughout. What I found is that the cold water is not flowing in to the WH from the T where it comes of the main cold line. The cold pipe gets very cold when a cold faucet is turned on further down from the T but the part of pipe that splits off to the WH remains same temp which is about room temperature. When both hot and cold are turned on from the nearest (bathroom) faucet, the hot pipe coming from the WH turns cold and I feel water traveling through it so I think the cold water is backing in to the WH from that faucet.
At this point should I turn off the valve above the WH where cold water should be coming in and check the nipple and pipe at that point for blockage?
Thank you!

I turned off and took of the cold water pipe going in to the WH, then fit a larger pipe over it (draining in to a bucket) and turned it on. Water came out, a bit dirty, but flowed OK. Now I know water is flowing in and out of both cold in and hot out (althought flowing cold in which is wrong direction, still flowing through) so it must be the nipple at the top of the WH tank or something inside the tank. Suggestions?
Thanks!

Yes if you read my post #3 I asked you to remove both nipple check if clogged, replace them if cloged the dirt the dirt indicates the nipples are cloged, Good Luck.

John

I'm trying to take the cold nipple off but it's stuck in the tank pretty good. My only pipe wrench is HUGE but I'm going to give it a try. Any other suggestions on how to get it out?
Thanks so much for all your help!

Spray some WD-40 at the end of both nipples let it to soak for a few minutes and try it after, good luck.

John

Couldn't get it off. Since it was 17 years old, a family friend offered to replace my WH and did so this afternoon. New hot water heater, warm water coming out of faucets. :)
But now, about 1 hour after friend left, pressure relief valve is dripping. Any ideas now? Thanks!

Couldn't get the nipple off. Asked a family friend for help. He offered to replace WH for me which we did this afternoon. Warm water at all faucets. :)
Problem is, about an hour after he left the pressure relief valve started dripping. No other leaks. Any suggestions?
Thanks!

I am glad that you got a new water heater and hot water.

Did the water heater came with T&P valve installed or he put the old one?

The T&P valve will leak for the following reasons,
1. If the water pressure is too high
2. If the gas valve is on high temperature setting
3. If there is dirt at T&P valve.

Do the following,

1. Check the water pressure it should be 45-60 psi.
2. Check the gas valve it should set at 120 degrees F.
3. Lift the arm on the T&P valve to release some pressure it let open for short time to drain some water if there is any dirt it will flush out
4, Open a hot side of a faucet in the house to bleed the air out.
If the above would not stop the leak then you have to replace the T&P valve, good luck and enjoy your hot water.

Regards,
John

The WH came with the PRV already installed in same place as old WH. There was no pipe on it so it was just dripping down the side of the tank to the floor. I rigged an old copper pipe to it that must have been used on a previous WH tank (not the last one) so that it now can route to a bucket.
I turned the heat down to 120. The friend must have accidentally set it at 130. The dripping has stopped and I will keep an eye on it.
Thanks so much for all of your help! It was really nice to have this forum available to educate me.
HAPPY HOLIDAYS!!

Hello Megakat,

I am gald that the fix the dripping, also you said that there was no drain line connected to the T&P valve, you have to connect a drain pipe and take it out side or place it close to a floor drain, to prevent you garage or your closet or where ever water heater is located from flooding in case the T&P valve leaks, see the image below, Thanks.

John